Author: John Au-Yeung

To handle errors thrown by require() module in Node.js, we use a try-catch block.

For instance, we write

let m;
try {
  m = require(modulePath);
} catch (e) {
  if (e.code !== "MODULE_NOT_FOUND") {
    throw e;
  }
  m = backupModule;
}

to wrap the require call in a try block.

And then we add a catch block that checks the error code.

If it’s not 'MODULE_NOT_FOUND', then we throw the e error.

Otherwise, we set m to backupModule.

To fix Error: getaddrinfo ENOTFOUND in Node.js for get call, we should make sure the URL is pointing to a valid location.

For instance, we write

const optionsGet = {
  host: "localhost",
  port: 3010,
  path: "/quote/random",
  method: "GET",
};

const reqGet = https.request(optionsGet, (res) => {});

to call https.request with the valid host and path to make a get request to https://localhost:3010/quote/random

To modify the Node.js request default timeout time, we set the timeout property.

For instance, we write

const http = require("http");
const server = http
  .createServer((req, res) => {
    setTimeout(() => {
      res.writeHead(200, { "Content-Type": "text/plain" });
      res.end("Hello World\n");
    }, 200);
  })
  .listen(1337, "127.0.0.1");

server.timeout = 20;
console.log("Server running at http://127.0.0.1:1337/");

to create a web server with createServer.

And we set the request timeout by setting the server.timeout property to a time milliseconds.

To store DB config in a Node.js and Express app, we store it in an .env file.

For instance, we write

DATABASE_PASSWORD=pw
DATABASE_NAME=some_db

in our .env file.

Then we write

require("dotenv").config();
const password = process.env.DATABASE_PASSWORD;

to load the .env file with the dotenv package.

And then we get the DATABASE_PASSWORD environment variable value with process.env.DATABASE_PASSWORD.

To fix ‘gulp’ is not recognized as an internal or external command with JavaScript, we install the gulp package.

To install it, we run

npm install -g gulp

to install gulp globally.